Patent GB-1416674-A (GB)
Title: Improvements relating to irrigation apparatus
IPC: A01G25/09
Filed: 1971-08-10
Abstract: 1416674 Irrigation machines G J P DOMINIC 10 Nov 1972 [10 Aug 1971] 37579/71 Heading AID [Also in Divisions B7 B8 F2 G3 and H4] An irrigation machine 10 comprises a tower 64 supporting two laterally extending spray booms 67 which, in operation, oscillate about a vertical axis, and a wheeled chassis 63 which supports the tower. The machine 10 is self propelled and has a guidance system to follow either an electric current carrying underground cable (Fig. 7) or a furrow in the ground (Fig. 8) or a pipeline forming part of the water supply to the machine. Water is suppiled to the machine from a hose connectible to hydrants located at various points in the area to be irrigated, whose hose may be mounted on reel pulled by the machine or a longitudinally seamed hose that is formed as the machine advances, by a device on the machine, from flexible strip material having interlocking edges, or from a flexible hose lying on the ground which hose is penetrated by a probe as the vehicle is guided by and/or advances along the hose (Fig. 21). Constructional Details:-Each boom comprises two outwardly convergent pipes 68 (not shown) and 69, which are braced by A frames 71 and cable 72, and an extension pipe 80. Spray nozzles are mounted at intervals along the pipes (68), 69 and the pipe 80 has a tip nozzle 83. A cable 22 is connected to the upper part of each boom 67 by which cable the booms may be pivoted upwardly from a horizontal position to a maximum inclination of 20‹. The tower 64 is oscillated about a vertical axis through an angle of 10‹ either by the reaction forces generated by a rotary and a non rotary water jet mounted on a respective one of the booms 67 or by cyclically-actuated hydraulic ram acting between the chassis 63 and the tower 64. Traction and Guidance. The chassis has rear wheels 61 which are driven off an I.C. engine and steerable front wheels 62 which are guided along a predetermined path by one of the following:-a. (see Fig. 7) a subterranean cable which carries an alternating or fluctuating current whose magnetic field is detected by two ferrite rod core inductors 90, 91 (Fig. 7) mounted on a tow bar at equal distances on either side of the fore and aft line of the vehicle. A solenoid valve 101A of differential amplifier detects any difference in the resultant voltages in the inductors and the error signal drives a steering linkage actuator 101 coupled to an Ackermann steering linkage 42 (see also Divisions G3 and H4) or b. (see Fig. 8) a furrow 107 in the ground's surface and along which a ground follower wheel 106 moves. The wheel 106 is carried by a drop arm 108 which is connected to a horizontal shaft 102. This shaft 102 is rotated about its longitudinal axis upon the wheel 106 passing along a bend in the furrow 107 and consequently a valve 110 which controls a ram (Fig. 8 not shown) coupled to the steering linkage 42 of the front wheels 62. Twin feeler arms in contact with the ground surface may be provided and these shut off the machine's engine should the wheel ride out of the furrow (see also Division B7) or c. a pipeline which is fixed to the ground and has, at spaced intervals, hydrants for connection of a hose coupled to the machine 10. A twin armed slider follows the fixed hose and steers the front wheels 62. or d. (see Fig. 21) a probe carried by the vehicle 10 and which draws water from a pipeline and at the same time guides the machine (see below). Water supply to the machine: Water may be supplied to the machine by a hose 50 which is connectible to hydrants at various fixed locations in the area being irrigated. To reduce the drag of this hose on the machine as it advances, the hose may be wound on a reel towed by the machine (see also Division B8). The reel is mounted on a trailer and is driven off the trailer's ground wheels via a chain and clutch drive or by a hydraulic motor and the hose is guided onto the reel by a traversing mechanism. Alternatively a length of flexible material is wound on a reel 203 carried by the machine (see Fig. 16). As the vehicle advances, the two edges of the material are interlocked by a former device 205 into a hose 212 whose end is connected to a hydrant and which receives a pipe 214 for feeding the water to the machine. In a third alternative (Fig. 21) a probe 222 pivots about a vertical pivot 223 on the machine and penetrates an opening in a longitudinally seamed hose to extract water. The opening is initiated and closed by a former device 221 which moves along the hose pipe. Pivoting of the probe actuates a control valve 224 of a hydraulic steering ram 225 coupled to the machine's steering linkage 42 in a manner providing positional feed back. The device 221 has two opposed channel sections which respectively receive the edges of the second hose to open and close them as the machine advances. In a modification of this third alternative, the probe is a collar which sealingly surrounds the pipe and has rollers which pinch the pipe to open the seam whereby water is fed from the hose to spray nozzles of the booms (see also Division F2). The machine carries a booster pump to suck water from the seamed hose via the probe.